This invention relates to voltage regulators. More particularly, it is concerned with solid state series voltage regulator apparatus for operation in an environment which may be subject to radiation.
Many types of voltage regulators which operate to provide a stable output voltage are well-known. A voltage regulator may be required, for example, to supply operating voltages to devices which are particularly sensitive to overvoltage conditions in order to prevent damage from transients caused by various occurrences. Voltage regulators commonly employ solid state devices such as transistors. However, solid state devices become highly conductive when exposed to radiation. Thus, if solid state regulators are subjected to radiation, the transistors become highly conductive permitting the output voltage of the regulator to vary out of control and possibly damage the devices the regulator is intended to protect.
An apparent solution in order to protect devices operating from a voltage regulator in an environment which is subject to radiation would be to employ a shunt type of voltage regulator. In voltage regulators of this type excess current would be bypassed away from the devices operating from the regulator output. However, for many applications there are problems in employing a shunt regulator. In particular, the amount of current flow and therefore the amount of energy to be dissipated may be exceptionally large under certain conditions.